Changeable-sign device



May 8, 1923.

H. w. CAIRN CHANGEABLE SIGN DEVICE Filed June 15,

'1920 s Sheets-Sheet 1 May 8,. 1923.

H. W. CAIRNS CHANGEABLE SIGN DEVICE Filed June 15, 1920 gnucnto z Amr/11mm 3 Sheen-Sheet 2 Patented May 8, 1923.

n rr er '1" s nanny W. CAIRNS, or DETROIT, moment.

CHANGEABLE-SIGN DEVICE.

Application filed June 15, 1929. Serial No. 389,089.

To all whom it may concern:

Be it known that I, HENRY \V'. CAIRNS, a citizen of the United States,residing at Detroit, in the county of Wayne and State 5 of Michigan,have invented a new and useful Changeable-Sign Device, of which thefollowing is a specification. V

This invention relates to changeable sign devices and more particularlyto devices for 1 successively exhibiting signs carried by a v webmounted on suitable rollers.

It is an object of the invention to provide an automatic mechanismdriven by the motor which actuates the rollers for starting said 1 motorat substantially uniform time intervals, and for stopping the same aftera travel of the web suflicient to register a different sign with thedisplay opening of the device. 4

A further object is to automatically reverse the motor by means of asuitable stepby-step mechanism upon a travel of the web in eitherdirection suflicient tocomplete d1splay of all of the signs. Among thedistinctive features of the 1nvention are the means employed to efiectillumination of the sign, and the provision for Variation in the speedof the rollers relative to the driving means therefor to compensate forthe varying driving efl'ectpf the web upon the reel from which 1t isbelng unwound.

The aforesaid objects are attained by the construction hereinafterdescribed and illustrated in ,the accompanying drawings, wherein,

Fig. 1 tion. v V

Fig. 2 is a side view of the same in partial section. I I Fig. 3 is adetail in horizontal cross-sec.-

tion of one of the uprights of the frame, the section being taken online 3 3 of Flg. 1.

Fig. 4c is a similar view of the lower cross member of the frame, theplane of section being indicated at 44 in Fig. 1.

Fig. 5 is a rear view of the device upon a somewhat larger scale thanthat of Fig. 1, certain parts being broken away to more clearly showportions of the operating mechanism. r

Fig. 6 is a detail view of a step-by-step mechanism for controlling themotor circuits, including a diagram of said circuits 55 Fig. 7 isanother view of said mechanism 1 transverse to Fig. 6.

is a front elevation of the inven- Fig. 1'." The uprights of the frame 5are preferably angle bar tresses (see Fig. 2) and these are rigidlyconnected at top and bottom by angle bars 6. There'is also extendedbetween the upper ends of said trusses an ornamental vertical plate 7carrying a clock 8, the dial of which is framed in "said plate, as seenin Fig. 1. A pilaster effect is given to each of the uprights of theframe by pressed sheet metal members 9, which serve also to concealelectric lamps 10 and to reflect the light thereof upon the displayedsign to illuminate the same. Lamps 11 are also provided above and belowthe sign to illuminate the same, and sheet metal members 12 serve toconceal said lamps to re-' fleet the light thereof upon the sign and toadd to the ornamental appearance of the frame.

The rollers 1 and 2 are mounted loosely upon shafts 13 journaled'in theframe and are concealed behind the memberslQ. A driving connection fromeach of said shafts to the corresponding roller is established by acoiled spring 141 recessed within one end portion of the roller, theconnections of said springs to the rollers and shafts being reverse sothat the tension on one'of said springs is being relieved while that ofthe other is increased, when both shafts are similarly driven. Amotor 15drives the lower shaft 13 through a speed reduction gearing 16, and theupper shaft 13 is driven from the lower through an endless chain 17, the

speed and direction of travel of the two shafts being the same. It ispreferred to arrange the motor 15 and drive gearing 16 at one side ofthe frame 5, and at the other side thereof to arrange within a casing 18an automatic motor control mechanism which will now be described'.Thus,'f upon an end of thelower roller 2 there is mounted fast a disk 19from which a pin 20 projects radially. An adjacent dislr21 carries uponone of its side faces .a plurality" of equally spaced pins 22, one ofwhich is engaged by the pin 20 of the disk 19 for each revolution of thelatter, so as to impart to said disk 21 a gradual step-by-step rotation. Adjacent the disk 21 is mounted a third disk 23 which has impartedthereto from the disk 21 a still more gradual stepby-step rotation.This" is effected by providing upon a side face of said disk 23 aplurality er equally spaced ins 24 equal in number to the signs on theweb 3, which pins are successively engageable by a r'adially projectingpin 25 upon the disk 21. Asshown, there are ten pins 22 upon the dis1'21, and seven ins 24 upon the disk 23. Thiis' ten revolutions of theinitial driving disk 19 are required to eliect a single turn of the disk21, and seven turns of the latter are necessary to accomplish arevolution of the disk 23, seven being also the number of signs carriedby the web 3. The disk 21 forms acontrol means for a switch 26 in themeter circuit 27 energized from the leads 27 and 27, and the disk 23 isadapted to control a reversing switch in series with the switch 26, andcomprising pivotal switch arm 23 and a pair of contacts 29 and 30, aforward or reverse drive of the motor being effected according as saidarm engages the contact 29 or 30. a A radial pin 31 on the disk 21 isengageable with the switch 26 to open the same as said pin reaches itsuppermost position, and a pair or radial pins 32 aujaeently mounted uponthe dial 23 are, one or the other, engageable with the switch arm 28,according to the direction in which said disk is being driven, to throwsaid switch arm from one to the other of the contacts 29 and 30 uponcompletion of a revolution of said disk. To insure immediate stopping ofthe disk 21 when the pin 31 opens the switch 26 and thus deener'gi'zesthe motor 115,21 coiled s rin 33 is mounted upon the stub shaft 34: ofsaid disk so as 'to bear upon the latter and exercise a braking effect.Thus, after the disk 21 has completed revolution andnpened the switch26, it remains a position to hold said switch open until the motor 15has been started by the means which will now be described. A normallyopen switch 35 controls ;a shunt 36 around the switch 26, and is itselfcontrolled by electro-magnet 37 being cl'osed when said magnet isenergized. The circuit '38 of said magnet includes a hand 39 whichrotates at a constant gradual rate, as for example, one revolution perminute, Said hand may conveniently be driven by one of the spindles (notshown) of the clock 8. "Once in each revolution said hand encounters acontact 40, also in the circuit 38, so that the electro-magnet '37 isenergized jdjuri'ng the brief period of contact of said hand with saidcontact. During this brief period, therefore, the switch '35 is closedand the motor is started. Before de-energization of the magnet 37, andconsequent opening of the switch 35, the disk 21 will have received atleast one rotative impulse, causing it to disengage the switch 26 andpermit the latter to close. Thus the switch 26 Will continue to closethe motor circuit subsequent to opening of the switch 35, and willmaintain said circuit closed until the completion of ten revclutionsofthe roller 2 and disk 19, and a resultant single revolution of the disk23, whereupon the pin 31 again opens the switch The proportioning of thesize of the signs on the web 3 to the diameter or the roller 2 is suchthat the travel of the Webfi accomanyingten revolution of the roller isjust sufiicie'nt to frame a dilferent sign in the opening 4. As thenumber of convolutio'ns' disk 23 effects the display or a difierent signand there are seven signs on the web,

they will be all displayed during the p H riod requiredto efi'ect onerevolution "of the disk 23. In completing its revolution said disk actsupon the switch arm 28, through one of the pins 32, and shifts the samefrom one to the other of the contacts 29 and 30, according to thedirection in which said disk is driven. Thus after a step-by-step travelof the web 3 in one di= recti'on sufficient to display all of the signsthereupon, an automatic reversal of the moto'r 15 is eliec-te'd so thata ste-p-by-step travel ofthe web in a reverse direction takes place.

WVhile there has been shown and described an embodiment of the inventionparticularly adapted for large outdoor displays, it is of course to beunderstood that the same inech anism might be employed for actuating asmaller device.

I claim is:

1. In a changeable sign, the combination with a pair of rolers and a webmounted thereon carrying a plurality of signs, or a frame provided withan opening across which said web travels, said opening beingproportioned for the display of "said signs individually, a motorhavinga drivingconnection with one of said rollers, a normally openswitch controlling the motor circuit, a shunt around said switch,,a second normally open switch in the shunt circuit, means for closing saidsecond switch to initially energize the motor, and mechanism driven bythe motor initially efiecting closing of the first-mentioned switch andopening the same and holding it open upon a travel of the web suflicientto display a diflerent sign through said opening.

2. In a changeable sign, the combination with a pair of rollers and aweb extending between said rollers "to alternately wind from one to theother, said web carrying a plurality of signs, of a frame provided withan opening across which said web travels, said opening beingproportioned for the dis play of said signs individually, a motor havingdriving connection with said rollers, allowing a speed differentialtherebetween, a normally closed reversing switch controlling said motor,a normally open switchfor the motor in series with said reversingswitch,

a step-by-sltepmechanism driven by the motor and having a cycle ofoperation initlially efleoting closing of said normally open switch andfinally opening the same, said mechanism completing its cycle duringtravel of the web sufficient to effect a change of signs, means forinitially energizing the motor at regular time intervals forperiodssufiicient to insure closing ofthe normally open switch, and astep-by-step mechanism driven by the motor in a relatively protractedcycle throwing over the reversing switch upon completion of said cycle,such completion being effected in substantial unison with completion ofthe desired travel of the web in either direction. In testimony whereofIsignthis specification.

HENRY W. CAIRNS.

